<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div {
            position: absolute;
            left: 0;
            width: 100px;
            height: 100px;
            background-color: pink;
        }
    </style>

</head>
<body>
    <div></div>
    <script>
        var div = document.querySelector('div');
        //手指初始坐标 startX startY
        var startX = 0;
        var startY = 0;
        //盒子原来坐标 x y
        var x = 0;
        var y = 0;
        div.addEventListener('touchstart', function(e){
            //获取手指初始坐标
            startX = e.targetTouches[0].pageX;
            startY = e.targetTouches[0].pageY;
            //获取盒子的初始坐标
            x = this.offsetLeft;
            y = this.offsetTop;
        })
        div.addEventListener('touchmove', function(e){
            //手指移动的距离 = 移动中的手指的坐标 - 手指的初始坐标
            var moveX = e.targetTouches[0].pageX - startX;
            var moveY = e.targetTouches[0].pageY - startY;
            //移动盒子
            //盒子最新的坐标=盒子初始坐标+手指移动的距离
            //记得单位加px
            this.style.left = x + moveX  + 'px';
            this.style.top = y + moveY  + 'px';
            //由于touchmove默认会触发屏幕滚动
            //加上e.preventDefault();阻止默认行为，加上后，手指移动带动盒子移动的时候，屏幕就不会滚动了
            e.preventDefault();

        })
    </script>
</body>
</html>